Grommet



FIG. 1 shows a top perspective view of my claimed design;

FIG. 2 shows a reduced top view of my claimed design;

FIG. 3 shows a reduced bottom view of my claimed design; and,

FIG. 4 shows a reduced side view of my claimed design of which the other side view is identical. 

The ornamental design for a grommet, as shown and described. 